A proposal to apply pesticides to invasive plant species on Cushing Island was put on hold Monday when a waiver request was delayed pending additional information.
The application by island resident John Spencer, president of the Cushing Island Conservation Corp., is for use on Asiatic bittersweet, bush honeysuckle, barberry, and black swallowwort, which he said have eliminated some native plants, including bayberry and sumac, and threaten other native plant species around the island.
But the pesticide ordinance waiver request got a divided response from a two-person subcommittee of the Pesticide Management Advisory Committee on Monday.
Waiver Committee member Avery Yale Kamila challenged several components of the application, ultimately saying Spencer’s best bet would simply be to remove the invasive species mechanically.
“My bigger concern is the wider ecosystem we’re all living in,” she said.
Kamila – who at times said Spencer’s application should be much more specific and suggested he could inventory every invasive plant on the island for a “threshold report” – said Portland specifically forbids “broadcast” application, which she interpreted as any kind of spray, including the handheld bottle Spencer was planning to use.
His request was to spray Roundup Concentrate Plus in a 1 percent solution, not to exceed 16 ounces a year. The application would likely occur in October when the island population is much smaller.
Although the other member of the subcommittee, city Sustainability Coordinator Troy Moon, disagreed with Kamila’s interpretation, Spencer said he would withdraw his application if he would not be permitted to use the spray bottle.
The last time he applied Roundup on the island he used a system where he cut the plants and applied drops of pesticide to the stems, which he said did not work.
“The bittersweet vines climb and eventually kill the native trees,” according to Spencer’s written request. “In addition, invasive shrubs, especially barberry, are known to harbor ticks.”
The request said “a variety of non-pesticide methods” have been employed in the past, including hand and mechanical removal, mowing, organic herbicides, and others. But the invasive species have always rebounded.
Ultimately, Spencer, Moon, and Kamila agreed to pause the application, with the hope that Moon and possibly Kamila would visit the island to see the invasive species. Spencer said he would add additional information to his application, such as a management plan and better numbers for the threshold report, although he said he is still confused about that request.
There was a similar waiver application to apply pesticides on Cushing Island in 2019, which was denied. However, City Manager Jon Jennings overruled the Pesticide Management Advisory Committee’s initial rejection of the waiver. His action made the Cushing application the city’s first waiver to the city’s pesticide ban.
The group did not seek another waiver in 2020.
Cushing Island is privately owned and provides no public access, although it is part of the city. Almost all the homes are occupied seasonally, except for a year-round island manager.